docs: def _build_sentence(word):
      """Builds a Pinyin sentence re pattern from a Pinyin word re pattern.
  
      A sentence is defined as a series of valid Pinyin words, punctuation
      (non-stops), and spaces followed by a single stop and zero or more
      container-closing punctuation marks (e.g. apostrophe and brackets).
  
      """
      return (
          "(?:{word}|[{non_stops}]|(?<![{stops} ]) )+"
          "[{stops}]['\"\]\}}\)]*"
      ).format(word=word, non_stops=non_stops.replace('-', '\-'),
               stops=stops)